EDIT: Since SOME people can't understand what an opinion is; THIS IS MY OPINION ON THE POPULARITY
from my study here's what I
know (edit for simplification)
BELIEVE about characters popularity:
DR MARIO: Not used by many, basically a slower version of Mario with a bit more knockback
LUIGI: Not used by many, a few setbacks that make him hard to use (His 'save' move is too vertical to help usually)
MARIO: Used moderately, the main mascot of Nintendo
BOWSER: Used infrequently, I don't know many people who can use slow characters well
PEACH: Used infrequently, not many people use Peach, although she has some of the most random, and potentially useful moves...
YOSHI: Used by few people, but usually very well by those people; Not having a "save" move really hurts popularity...
DONKEY KONG: Nearly unused, I don't know of many people who do or can play well as DK, unfortunately you'll never see another Kong on SSB because Rare was bought by Microsoft, so DK is the only one that Nintendo has full rights to
CAPTAIN FALCON: Almost totally unused, those that DO use him are usually good with him...
GANONDORF: Rarely used, I've only seen 2 people who use Ganondorf...
FALCO: My cousin's favorite, if used properly, can be VERY lethal
FOX: I like Foxes ^^; oh... wait... Fox is usually used less than Falco if Falco is unlocked, but can be more irritating and potentially difficult to beat
NESS: I know of like 1 person who uses Ness, his "save" move is very hard to use
ICE CLIMBERS: Probably the least used character on the list... I know of people who are fantastic with them though
KIRBY: A favorite character by some, I am not very good, but can use Kirby
SAMUS: Almost overused, popular among all classes of players, strong attacks, fairly fast, and good range
ZELDA: Less used than...
SHEIK: Used more than Zelda, unsure why, Zelda can be very effective, but Sheik is highly effective.
LINK: Overused, from here on, part of my description for this type of character is "has a sword," all 4 overused characters have swords, and while a couple have a range of abilities, I usually see the same 4 moves used
YOUNG LINK: Overused, has a sword, see Link, but with FIRE ARROWS! woo?
PICHU: My personal favorite, s/he lets me play as Pikachu, without playing as the character I so loathe... Used by a few people, usually people who are stunning at using the character, "easiest to throw off a ledge" lightest character, VERY fast, pretty strong, and even though he is light, I have played against VERY good players and survived up to 250% with no handicap/damage editing
PIKACHU: The character I am best with (other than Pichu,) the character I learned to play with, oddly, I have NEVER liked Pikachu when I've played Super Smash Bros, but the moveset suits me... The uses of this character are more frequent that its counterpart, and not always as proficient of a player, but can be used real well...
JIGGLYPUFF: Underused, I know of ONE person who uses Jigglypuff on a regular basis, and he is one of only 4 people to have beaten me on more than one occasion at Gamers' Club (we almost always play SSB:M at Gamers' Club)
MEWTWO: A character I can do well with, despite the characters' speed, not oft used, however can be used well
MR. GAME AND WATCH: My other favorite, so goofy, I enjoy them putting Gunpei Yokoi's (may he rest in peace) first 'character' in this game, one of the characters who you're not always sure what you're gonna get
a fun character to mess around with, and not all that weak either! Great "save" move
MARTH: THE MOST OVERUSED, I am one of the only people I know who does not like Marth, I don't like Marth mainly because so many people do like him, I have had numerous 4 person matches where I'm the only non-Marth, has a sword, one of the few characters to be used so much I can't stand them...
ROY: Overused, but the least so of the "has a sword" category... I guess the "weaker" counterpart of Marth, a bit slower, perhaps equal knockback, and a charge attack that hurts him if not used right, but he has a fire sword!
SUPER SMASH BROS ONLY:
LUIGI: Fairly unused
MARIO: More oft used than Luigi
DONKEY KONG: Infrequent use
YOSHI: Used by a few people real well
CAPTAIN FALCON: Used by a few people
NESS: Not used much
FOX: Used infrequently
SAMUS: Most overused in the original SSB
LINK: Second most overused, has a sword
PIKACHU: The character I use the most
JIGGLYPUFF: Used specifically by the same player as before
RANT/INPUT OVER
